A server SHOULD indicate that it supports storing attributes with
language tag options in the DIT by publishing 1.3.6.1.4.1.4203.1.5.4
as a value of the root DSE.

It should say:

A server SHOULD indicate that it supports storing attributes with
language tag options in the DIT by publishing 1.3.6.1.4.1.4203.1.5.4
as a value of the "supportedFeatures" [RFC3674] attribute of the root
DSE.

Notes:

In section 5, it says:

Implementators of this specification should take care that their use
of language tag options does not impede proper function of
implementations which do not support language tags.

It should say:

Implementors of this specification should take care that their use
of language tag options does not impede proper function of
implementations which do not support language tags.